package LC;

import java.util.Arrays;

/**
 * https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/
 * Given an array of integers that is already sorted in ascending order,
 * find two numbers such that they add up to a specific target number.
 * The function twoSum should return indices of the two numbers such that they add up to the target,
 * where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.
 * You may assume that each input would have exactly one solution and you may not use the same element twice.
 * Input: numbers={2, 7, 11, 15}, target=9
 * Output: index1=1, index2=2
 */
public class LC_167_TwoSumIIInputarrayissorted_TwoPointers_BinarySearch {
    public static void main(String[] args) {
        System.out.println(Arrays.toString(Solution.twoSum(new int[]{1, 2, 3, 5, 5, 6}, 10)));
    }

    static class Solution {
        static int[] twoSum(int[] numbers, int target) {
            if (numbers == null || numbers.length < 1) return null;
            int i = 0, j = numbers.length - 1;
            while (i < j) {
                int x = numbers[i] + numbers[j];
                if (x < target)
                    ++i;
                else if (x > target)
                    --j;
                else
                    return new int[]{i + 1, j + 1};
            }
            return null;
        }
    }
}